(function($) {

    $.widget("ui.accordion", {

        _init: function() {

            var o = this.options, self = this;
            this.running = 0;

            if (o.navigation) {
                var current = this.element.find("a").filter(o.navigationFilter);
                if (current.length) {
                    if (current.filter(o.header).length) {
                        this.active = current;
                    } else {
                        this.active = current.parent().parent().prev();
                        current.addClass("ui-accordion-content-active");
                    }
                }
            }

            this.element.addClass("ui-accordion ui-widget ui-helper-reset");

            this.headers = this.element.find(o.header).addClass("ui-accordion-header ui-helper-reset ui-state-default ui-corner-all")
			.bind("mouseenter.accordion", function() { $(this).addClass('ui-state-hover'); })
			.bind("mouseleave.accordion", function() { $(this).removeClass('ui-state-hover'); });

            this.headers
			.next()
				.addClass("ui-accordion-content ui-helper-reset ui-widget-content ui-corner-bottom");

            this.active = this._findActive(this.active || o.active).toggleClass("ui-state-default").toggleClass("ui-state-active").toggleClass("ui-corner-all").toggleClass("ui-corner-top");
            this.active.next().addClass('ui-accordion-content-active');

            //Append icon elements
            $("<span/>").addClass("ui-icon " + o.icons.header).prependTo(this.headers);
            this.active.find(".ui-icon").toggleClass(o.icons.header).toggleClass(o.icons.headerSelected);

            // IE7-/Win - Extra vertical space in lists fixed
            if ($.browser.msie) {
                this.element.find('a').css('zoom', '1');
            }

            this.resize();

            //ARIA
            this.element.attr('role', 'tablist');

            this.headers
			.attr('role', 'tab')
			.bind('keydown', function(event) { return self._keydown(event); })
			.next()
			.attr('role', 'tabpanel');

            this.headers
			.not(this.active || "")
			.attr('aria-expanded', 'false')
			.attr("tabIndex", "-1")
			.next()
			.hide();

            // make sure at least one header is in the tab order
            if (!this.active.length) {
                this.headers.eq(0).attr('tabIndex', '0');
            } else {
                this.active
				.attr('aria-expanded', 'true')
				.attr('tabIndex', '0');
            }

            // only need links in taborder for Safari
            if (!$.browser.safari)
                this.headers.find('a').attr('tabIndex', '-1');

            if (o.event) {
                this.element.bind((o.event) + ".accordion", function(event) { return self._clickHandler.call(self, event); });
            }

        },

        destroy: function() {

            this.element
			.removeClass("ui-accordion ui-widget ui-helper-reset")
			.removeAttr("role")
			.unbind('.accordion')
			.removeData('accordion');

            this.headers
			.unbind(".accordion")
			.removeClass("ui-accordion-header ui-helper-reset ui-state-default ui-corner-all ui-state-active ui-corner-top")
			.removeAttr("role").removeAttr("aria-expanded").removeAttr("tabindex");

            this.headers.find("a").removeAttr("tabindex");
            this.headers.children(".ui-icon").remove();
            this.headers.next().removeClass("ui-accordion-content ui-accordion-content-active");

        },

        _keydown: function(event) {

            var o = this.options, keyCode = $.ui.keyCode;

            if (o.disabled || event.altKey || event.ctrlKey)
                return;

            var length = this.headers.length;
            var currentIndex = this.headers.index(event.target);
            var toFocus = false;

            switch (event.keyCode) {
                case keyCode.RIGHT:
                case keyCode.DOWN:
                    toFocus = this.headers[(currentIndex + 1) % length];
                    break;
                case keyCode.LEFT:
                case keyCode.UP:
                    toFocus = this.headers[(currentIndex - 1 + length) % length];
                    break;
                case keyCode.SPACE:
                case keyCode.ENTER:
                    return this._clickHandler({ target: event.target });
            }

            if (toFocus) {
                $(event.target).attr('tabIndex', '-1');
                $(toFocus).attr('tabIndex', '0');
                toFocus.focus();
                return false;
            }

            return true;

        },

        resize: function() {

            var o = this.options, maxHeight;

            if (o.fillSpace) {

                if ($.browser.msie) { var defOverflow = this.element.parent().css('overflow'); this.element.parent().css('overflow', 'hidden'); }
                maxHeight = this.element.parent().height();
                if ($.browser.msie) { this.element.parent().css('overflow', defOverflow); }

                this.headers.each(function() {
                    maxHeight -= $(this).outerHeight();
                });

                var maxPadding = 0;
                this.headers.next().each(function() {
                    maxPadding = Math.max(maxPadding, $(this).innerHeight() - $(this).height());
                }).height(maxHeight - maxPadding)
			.css('overflow', 'auto');

            } else if (o.autoHeight) {
                maxHeight = 0;
                this.headers.next().each(function() {
                    maxHeight = Math.max(maxHeight, $(this).outerHeight());
                }).height(maxHeight);
            }

        },

        activate: function(index) {
            // call clickHandler with custom event
            this._clickHandler({ target: this._findActive(index)[0] });
        },

        _findActive: function(selector) {
            return selector
			? typeof selector == "number"
				? this.headers.filter(":eq(" + selector + ")")
				: this.headers.not(this.headers.not(selector))
			: selector === false
				? $([])
				: this.headers.filter(":eq(0)");
        },

        _clickHandler: function(event) {

            var o = this.options;
            if (o.disabled) return false;

            // called only when using activate(false) to close all parts programmatically
            if (!event.target && !o.alwaysOpen) {
                this.active.removeClass("ui-state-active ui-corner-top").addClass("ui-state-default ui-corner-all")
				.find(".ui-icon").removeClass(o.icons.headerSelected).addClass(o.icons.header);
                this.active.next().addClass('ui-accordion-content-active');
                var toHide = this.active.next(),
				data = {
				    options: o,
				    newHeader: $([]),
				    oldHeader: o.active,
				    newContent: $([]),
				    oldContent: toHide
				},
				toShow = (this.active = $([]));
                this._toggle(toShow, toHide, data);
                return false;
            }

            // get the click target
            var clicked = $(event.target);

            // due to the event delegation model, we have to check if one
            // of the parent elements is our actual header, and find that
            // otherwise stick with the initial target
            clicked = $(clicked.parents(o.header)[0] || clicked);
            var clickedIsActive = clicked[0] == this.active[0];

            // if animations are still active, or the active header is the target, ignore click
            if (this.running || (o.alwaysOpen && clickedIsActive)) {
                return false;
            }
            if (!clicked.is(o.header)) {
                return;
            }

            // switch classes
            this.active.removeClass("ui-state-active ui-corner-top").addClass("ui-state-default ui-corner-all")
			.find(".ui-icon").removeClass(o.icons.headerSelected).addClass(o.icons.header);
            this.active.next().addClass('ui-accordion-content-active');
            if (!clickedIsActive) {
                clicked.removeClass("ui-state-default ui-corner-all").addClass("ui-state-active ui-corner-top")
				.find(".ui-icon").removeClass(o.icons.header).addClass(o.icons.headerSelected);
                clicked.next().addClass('ui-accordion-content-active');
            }

            // find elements to show and hide
            var toShow = clicked.next(),
			toHide = this.active.next(),
			data = {
			    options: o,
			    newHeader: clickedIsActive && !o.alwaysOpen ? $([]) : clicked,
			    oldHeader: this.active,
			    newContent: clickedIsActive && !o.alwaysOpen ? $([]) : toShow.find('> *'),
			    oldContent: toHide.find('> *')
			},
			down = this.headers.index(this.active[0]) > this.headers.index(clicked[0]);

            this.active = clickedIsActive ? $([]) : clicked;
            this._toggle(toShow, toHide, data, clickedIsActive, down);

            return false;

        },

        _toggle: function(toShow, toHide, data, clickedIsActive, down) {

            var o = this.options, self = this;

            this.toShow = toShow;
            this.toHide = toHide;
            this.data = data;

            var complete = function() { if (!self) return; return self._completed.apply(self, arguments); };

            // trigger changestart event
            this._trigger("changestart", null, this.data);

            // count elements to animate
            this.running = toHide.size() === 0 ? toShow.size() : toHide.size();

            if (o.animated) {

                var animOptions = {};

                if (!o.alwaysOpen && clickedIsActive) {
                    animOptions = {
                        toShow: $([]),
                        toHide: toHide,
                        complete: complete,
                        down: down,
                        autoHeight: o.autoHeight || o.fillSpace
                    };
                } else {
                    animOptions = {
                        toShow: toShow,
                        toHide: toHide,
                        complete: complete,
                        down: down,
                        autoHeight: o.autoHeight || o.fillSpace
                    };
                }

                if (!o.proxied) {
                    o.proxied = o.animated;
                }

                if (!o.proxiedDuration) {
                    o.proxiedDuration = o.duration;
                }

                o.animated = $.isFunction(o.proxied) ?
				o.proxied(animOptions) : o.proxied;

                o.duration = $.isFunction(o.proxiedDuration) ?
				o.proxiedDuration(animOptions) : o.proxiedDuration;

                var animations = $.ui.accordion.animations,
				duration = o.duration,
				easing = o.animated;

                if (!animations[easing]) {
                    animations[easing] = function(options) {
                        this.slide(options, {
                            easing: easing,
                            duration: duration || 700
                        });
                    };
                }

                animations[easing](animOptions);

            } else {

                if (!o.alwaysOpen && clickedIsActive) {
                    toShow.toggle();
                } else {
                    toHide.hide();
                    toShow.show();
                }

                complete(true);

            }

            toHide.prev().attr('aria-expanded', 'false').attr("tabIndex", "-1");
            toShow.prev().attr('aria-expanded', 'true').attr("tabIndex", "0").focus();

        },

        _completed: function(cancel) {

            var o = this.options;

            this.running = cancel ? 0 : --this.running;
            if (this.running) return;

            if (o.clearStyle) {
                this.toShow.add(this.toHide).css({
                    height: "",
                    overflow: ""
                });
            }

            this._trigger('change', null, this.data);
        }

    });


    $.extend($.ui.accordion, {
        version: "1.6rc6",
        defaults: {
            active: null,
            autoHeight: true,
            alwaysOpen: true,
            animated: 'slide',
            clearStyle: false,
            event: "click",
            fillSpace: false,
            header: "a",
            icons: {
                header: "ui-icon-triangle-1-e",
                headerSelected: "ui-icon-triangle-1-s"
            },
            navigation: false,
            navigationFilter: function() {
                return this.href.toLowerCase() == location.href.toLowerCase();
            }
        },
        animations: {
            slide: function(options, additions) {
                options = $.extend({
                    easing: "swing",
                    duration: 300
                }, options, additions);
                if (!options.toHide.size()) {
                    options.toShow.animate({ height: "show" }, options);
                    return;
                }
                var hideHeight = options.toHide.height(),
				showHeight = options.toShow.height(),
				difference = showHeight / hideHeight,
				overflow = options.toShow.css('overflow'),
				showProps = {},
				hideProps = {},
				fxAttrs = ["height", "paddingTop", "paddingBottom"];
                $.each(fxAttrs, function(i, prop) {
                    hideProps[prop] = 'hide';
                    showProps[prop] = parseFloat(options.toShow.css(prop));
                });
                options.toShow.css({ height: 0, overflow: 'hidden' }).show();
                options.toHide.filter(":hidden").each(options.complete).end().filter(":visible").animate(hideProps, {
                    step: function(now, settings) {
                        // if the alwaysOpen option is set to false, we may not have
                        // a content pane to show
                        if (!options.toShow[0]) { return; }

                        var percentDone = settings.start != settings.end
						? (settings.now - settings.start) / (settings.end - settings.start)
						: 0,
						current = percentDone * showProps[settings.prop];
                        if ($.browser.msie || $.browser.opera) {
                            current = Math.ceil(current);
                        }
                        options.toShow[0].style[settings.prop] = current + 'px';
                    },
                    duration: options.duration,
                    easing: options.easing,
                    complete: function() {
                        if (!options.autoHeight) {
                            options.toShow.css("height", "auto");
                        }
                        options.toShow.css({ overflow: overflow });
                        options.complete();
                    }
                });
            },
            bounceslide: function(options) {
                this.slide(options, {
                    easing: options.down ? "easeOutBounce" : "swing",
                    duration: options.down ? 1000 : 200
                });
            },
            easeslide: function(options) {
                this.slide(options, {
                    easing: "easeinout",
                    duration: 700
                });
            }
        }
    });

})(jQuery);